AK Build Almost complete

[awptickes]

Correct.

Meh, I'd rather hit stuff with a hammer than weld.

 

[rob-cubed]

Meh, I'd rather hit stuff with a hammer than weld.

"It is tempting, if the only tool you have is a hammer, to treat everything as if it were a nail." -Abraham Maslow, 1966

Nothing wrong with hammer-setting rivets though. It works.

Nice TIG job by the way!

 

[awptickes]

So,

I took it to the range and put 10 rounds through it, but none in semi auto. It's essentially a magazine fed bolt gun. It's a matter of the upper rails not fitting the bolt carrier correctly I think. It gets caught on the second opening on the right side, I've attached a picture of the area on the receiver.

I'm thinking about filling down the bolt carrier's right rail guide to get a slope that will work. The hammer is pushing up the action, causing the action's right rail guide to get caught in the highlighted portion. Anyone have any ideas? I've already filed, smoothed, polished, and reblued the hammer and the bottom of the bolt carrier (also picture attached and hilighted) where it touches the hammer, it works better, but not 100% yet.

Is this a common problem? Other than that, It's just a few minor little file issues of cleaning up parts, getting things to move with enough clearance to work all of the time.

 

[awptickes]

Some quick research shows that a buffer may do the trick. Thoughts?

 

[rob-cubed]

I haven't had this issue on any of my builds, but others have:
- Replaced the recoil spring assembly
- Added a buffer

Did your other build work fine? I would try switching the recoil spring assembly between the two first. A weak spring or a rod that sits up too high can cause this issue. One guy couldn't figure it out and eventually realized that the end that locks into the rear trunnion was sitting up to high, and guiding the carrier upwards. He ground some material off the bottom and it solved it.

 

[jdramsey]

I've got buffers in both of mine, and have never had the carrier catch on the rail like that. Be careful filing the hammer and bottom of the carrier. The hammer should push up on the carrier a bit, cause the carrier has to push the hammer down till it engages the disconnector's hook. On my Yugo, I did have to open up the groove on each side of the bolt carrier, that the top rail rides in. You should be able to flair the very end of those groves and bit. Make them sort of funnel shaped at the very end of the groove. And taper the top rail where it's catching. You don't want any sharp corners or edges on those top rails. I filed mine and then smoothed them up with sand paper. I'll post a picture of my rails when I get home.

 

[aquaman]

those are not stepped rails are they?

 

[leroygibbs]

How does the bolt carrier (and bolt) fit and move in the reciever without the trigger and pins in it? If it moves freely and easily, that should tell you the upper rails are OK. My general rule of thumb is don't touch the bolt or carrier.

Really stupid question, is it your pistol grip screw (and nut) in right? I had a similar issue, but it was a stupid case of a wood pistol grip hole being too big, so the screw was above the square nut, causing things to bump, and giving me a single shot AK....

 

[awptickes]

Everything is in tightly fitting. I will take pictures of the places where it jams consistently. It looks like it might just be the bolt not lining up correctly in the carrier when the forward stroke takes place after the gas forces it back.

The little notch in the bolt where the ejector prong on the rail fits doesn't fit, because the bolt rotates counterclockwise (looking from the butt forward) as the carrier comes back. I might change the slope of the ejector prong a bit in hopes that I can mitigate this, but other than that little hangup it's fine.

Curiously, when cycling it by hand with the barrel pointing down, it works fine.

 

[leroygibbs]

Ok. So, if you take the bolt out of the carrier, and cycle it by hand, does it work well?

If the bolt is hitting or hanging on the ejectotr time, you may need to trim the ejector on the rail, or at least sand it down a very little bit at a time.

 

[awptickes]

Ok. So, if you take the bolt out of the carrier, and cycle it by hand, does it work well?

If the bolt is hitting or hanging on the ejectotr time, you may need to trim the ejector on the rail, or at least sand it down a very little bit at a time.

Without the bolt, it cycles very well.

I'll probably grind/file down the ejector until it cycles by hand, then it'll be good to go.

 

[awptickes]

Went to work tonight on the extractor/ejector with the dremel, got that trimmed, then used the hammer a bit. Also, curiously, the top cover provides spring to the carrier handle, and forces the carrier down slightly to ride on the lower/inner rails. After bending the top cover a bit more, it worked better. All this, and I have a fairly successful build.

Now it works. I successfully shot three rounds in semi-auto succession. I only have been loading the magazines with 3 to 5 rounds in case of a run away, but I think I'll fill it up next time.

I still have some odd FTF problems, but I think I solved those too. Next trip to the range will tell. So far 60 rounds, and I think I have all the kinks worked out. The FTF is a problem with the magwell, which I think I fixed.

 

[awptickes]

Pics.

 

[rob-cubed]

Right on, glad you got 'er running.

The thing about AKs, nothing a little filing or a hammer usally won't fix!

 

[awptickes]

I picked up a bunch of ammo, a handful of inert rounds, and 100 blanks from the Timonium Gun Show. I think I have the feed issues resolved. I'll find out today at the range.

EDIT: Also, I'll find out if the blanks will cycle the action fully. A lot of people don't think it will.

 

[leroygibbs]

In my experience, it depends on the blanks.... I remember buying some East German ones a while back ago that cycled fine, but in more recent times, the Bear blanks didn't do it.... YMMV.

Still fun, but play with blanks carefully, and use the Blank Fire Adapter.

 

[awptickes]

I have a blank adapter coming in the mail. I'll save the blanks for new years or something.

So, I have the action working smoothly, now it's just a feed issue with the LEFT side of the magazine. If I manually load a round in the chamber, then let it cycle semi-auto it will load the round on the right. Every single round on the right feeds properly, sometimes (about 7 times in 60 rounds tonight) a round on the left will feed properly, but generally the answer is JAM, no round loaded, or round half-loaded.

Any ideas?

 

[mdshooterguy2820]

Probably could have concentrated better if that jerk at the other end of the range didn't keep shooting that .22 off while you were trying to work

 

[rob-cubed]

Every single round on the right feeds properly, sometimes (about 7 times in 60 rounds tonight) a round on the left will feed properly, but generally the answer is JAM, no round loaded, or round half-loaded.

Any ideas?

Usually an issue with the mag sitting too low. Not enough contact between the bolt and the round. Are the feed lips tight up against the rail and parallel to it? Does the back of the mag drop lower? Any play at all?

The selector stop can be ground down to adjust the fit of the mag to the height of the rails. Unfortunately you'd have to remove the trigger guard to do so.

 

[awptickes]

There's some side-to-side play in the mag, depending on the type of mag I use. The feed lips don't sit exactly parallel to the inner rails, but I think I can fix this with a hammer, as the bottom of the receiver is slightly convex.